Stop motion for knitting machines



Oct. 1, 1935. J. A. LOCKE ET AL STOP MOTION FOR KNITTING MACHINES Filed April 22, 1955 5 Sheets-Sheet 1 Oct. 1, 1935. J, A. LOCKE El AL 2,016,208

STOP MOTION FOR KNITTING MACHINES Filed April 22, 1953 3 Sheets-Sheet 2 Oct. 1, 1935. J. A. LQCKE ET AL 2,016,208

STOP MOTION FOR'KNITTING MACHINES Filed April 22, 1933 3 Sheets- Sheet 3 Patented Oct. 1, 1935 UNITED STATES PATENT OFFICE STOP MOTION FOR. KNITTING MACHINES Application April 22, 1933, Serial No. 667,442

14 Claims. ,(01. 66157) This invention relates to improvements in circular knitting machines, and particularly to the type known as the Standard machine. During the operation of these machines it frequently occurs that the latch of a needle fails to open when the needle rises after being operated, by the knitting cams, to take thread and to cast the previously formed stitch. During all subsequent knitting cycles, in which the needle latch remains closed, that particular needle will fail to knit and the thread held in the hook of the needle by the closed latch will eventually break. In some instances, previous breaking of the thread of a newly formed loop on a needle will cause failure of the latch of the needle to open. In either case, imperfect fabric will result and the imperfections frequently are not detected by the operator until the initial portion of the imperfect fabric has passed down through the needle cylinder, after the knitting of a great number of courses.

In some instances the butt of a needle becomes broken and in place of the needle descending to cast a stitch the needle will remain in the latchclearing position and will fail to knit in subsequent courses. Failure of the needle to operate with the other needles throughout the entire cam wave frequently produces what is known as a smash, wherein a large number of needles are often broken and bent, necessitating the machine remaining idle for a long period while repairs and replacement of parts and needles are being made.

In other instances the retaining band, which maintains the needle-controlling jacks in operative position in the jack ring, breaks or stretches to such an extent that the jacks are permitted to slide out radially under the influence of centrifugal force produced by the rapidly rotating cylinder and jack ring, whereupon the jacks will strike stationary portions of the machine adjacent the rotating cylinder and jack ring which results in the smash of considerable magnitude.

The object of the present invention is to provide mechanism which will immediately detect a closed needle latch within a small segment of the circle described by the needles wherein all latches should be open; an inoperable needle disposed in an elevated position at a point along the cam wave in which such needle should be in a depressed position; or a jack projecting radially beyond the normal circular path prescribed by the outer ends of the jacks.

Another object of the invention is to utilize the above noted detection of faulty operation of the elements noted to stop the machine immediately, thereby avoiding the formation of imperfect fabric and preventing the costly smashes, whereby a material financial saving to the manufacturer using these machines is effected.

The construction and operation of the mechanism forming the subject matter of the present invention and its cooperation with other standard parts of a machine of the type noted will be fully disclosed hereinafter, reference being had to the accompanying drawings; of which:

Fig. 1 is a perspective view showing the mechanism of the present invention applied to a machine of the type noted, only such parts of the Standard machine as are immediately concerned with the operation of the mechanism of the present invention being shown;

Fig. 2 is an enlarged plan view illustrating the normal relation between the closed latch and elevated needle detector with the needles of the machine;

Fig. 3 is a sectional elevation taken on the line 33, Fig. 2;

Fig. 4 is an enlarged plan view, partly in section, illustrating the relation of the extended jack detector with the jacks of the machine;

Fig. 5 is a sectional elevation taken on the line 55, Fig. 4; i

Fig. 6 is an-enlarged plan view, partly in section, showing the belt shipper of the machine and the tripping mechanism, forming part of the present invention, in cooperative relation thereto; and

Fig. '7 is a sectional view taken on the line 1-1, Fig. '1.

The machine chosen for the purpose of illustrating the present invention is of the conventional Standard type adapted for knitting plain and/or fancy hosiery. The machine is equipped with mechanism for producing continu- 40 ous circular leg and foot knitting and reciprocatory heel and toe knitting. Only such parts of the machine as directly affect, and those directly affected by, the mechanism forming the subject matter of the present invention have been shown in the drawings of the present application, all other parts of the machine having been omitted for the purpose of clearness.

The machine comprises a frame I which includes a base plate 2 and a bed plate 3. To the bed plate 3 is secured a head 4 in which is rotatably mounted the needle cylinder 5, encircled by the concentric jack ring 6. Operatively mounted in the cylinder 5 are latch needles I, 1 which are adapted, in producing certain kinds of work,

to be acted upon'by jacks 8, 8, respectively, which are radially disposed in the jack ring 6 and maintained therein against centrifugal force by a spring band 9.

The machine is also provided with a pair of relatively vertically spaced pinions I I! and II respectively which are rotatably mounted in fixed horizontal planes for free rotation on a vertical shaft I2. Splined to the shaft I2 is a clutch collar I3 which is adapted to be shifted axially of the shaft into engagement with clutch jaws on the underside of the upper pinion II) to eifect continuous rotation of the cylinder 5 in the direction of the arrow a, Fig. 1, during the knitting of the leg and foot of a stocking.

The clutch collar I 3 is also adapted to be shifted into engagement with clutch jaws on the lower pinion II for effecting oscillatory movement of the needle cylinder 5 during the knitting of the heel and toe. The shifting of the clutch collar I 3, in the present instance, is effected by mechanism of the character disclosed in the U. S. Patent to H. E. Houseman, No. 1,364,112, dated January 4, 1921, said patent being one of a number of patents covering various features of the present day Standard machine as sold on the market.

The shifting of the clutch collar I3 is effected through the medium of a shifter fork I4 which is slidably mounted on a'vertical shaft I5. On the shifter fork I4 is pivotally mounted a trip shaft I6 which is arranged to be rocked by suitable pattern mechanism (not shown) for stopping the machine at predetermined times, such, for

example, as at the completion of a stocking, at whichtime the stopping of the machine is accomplished by a forked lever I'I secured to the lower end of the trip shaft I6 and engaging a vertical pin I8 that is secured in and projects above and below a latch I9 that is pivotally mounted at 2!) on a bracket ZI rigidly secured to the frame of the machine. Slidably mounted in the bracket 2! is a shipper rod 22 to which is secured the belt shipper 23. The lower end of the pin I8 is engaged by an abutment 24 on the belt shipper 23 and retains the shipper in position to maintain the main driving belt of the machine on the tight pulley of the machine (not shown), against the action of a spring 25 which encircles the shipper rod 22 between one side of the belt shipper 23 and a bearing 26 of the bracket 2|. The latch I9 and lever I'I comprise a sort of toggle joint for locking the shipper 23 in an operative position, movement of the latch I9 in one direction being limited by its engagement with one arm 21 of the resetting lever 28 which is pivotally mounted at 29 on the bracket 2|.

When the trip shaft I6 is rocked about its axis in the direction of the arrow 2) (Fig. l), the latch I9 is also swung about its pivot 20, through the medium of the arm I I on the trip shaft I6 engaging the upper end of the pin I8 carried by the latch I 9. Rocking of the trip shaft I6 breaks the toggle and the belt shipper 23 is then moved to the right, as viewed in Figs. 1 and 6, by the spring 25 to shift the belt from the tight to the loose pulley of the machine, thereby bringing the machine to a stop.

The mechanism so far described is common to the type of machine referred to and the mechanism hereinafter described is that constituting the subject matter of the present invention.

Secured to the head 4 is a pedestal 30. The head 3| of the pedestal 30 is grooved, as at 32, for the reception of a longitudinally slidable support 33 which is normally projected toward the needle cylinder 5 by springs 34, 34.

Pivotally mounted on a post 35 secured to and projecting above the slide 33 is the needle detector 36, shown in detail in Fig. 2. The inner end of the needle detector 36 is of a forked construction and constitutes a pair of tines 3! and 38 respectively. The tine 38 is bent at right angles to the main body of the detector, as illustrated at 39 (Figs. 2 and 3), the bent end 39 being disposed substantially parallel to the plane of rotation of the needles I, in a plane directly below that assumed by the points 4!) of the hooks of the needles I after'said needles have been raised to an elevation wherein the previously formed stitches on the needles lying behind the latches 4i thereof have moved downwardly on the needles to a position wherein such stitches have caused the said latches 4! to open ready to receive a new thread under the points of the hooks 46 of the needles.

Should the latch of a needle fail to open for any, reason as the needles rise to the position noted, sucha closed latch, as illustrated at M a in Figs. 2 and 3, will be engaged by the bent end 39 of the needle detector 36, the said end 39 entering the space between the back of the closed latch and the front of the cheek of the needle. The closed latch engages the tine 38 of the needle detector 36 as the needles move in the direction of the arrow shown in Fig. 2, thereby swinging the needle detector 36 about its pivot 35, which, ef. fects immediate stopping of the machine in a manner hereinafter described. The bent end or book 39 on the tine 38 holds the latch 4| so that the detector 36 will be positively actuated by the closed latch.

In the cases where a needle, such as that illustrated at la in Fig. 3, has not been lowered by the knitting cams, which frequently occurs as a result of a defective or broken butt on the needle, such needle, by reason of its being in a position relatively higher than the needles adjacent thereto as the needles move beneath the tine 31 of the needle detector 36, will strike the tine 3! and swing the needle detector 36 about its pivot 35, to effect immediate stopping of the machine as referred to above.

The needle detector 36 is provided with an outwardly extending arm 42, one side of which is normally engaged by a finger 43 projecting vertically from an outwardly extending arm 44 of a jack detector 45 (see Fig. 4), said jack detector being pivoted at 46 in a horizontal cavity 4? formed in one side of the pedestal 3|. The jack detector 45 is provided with an inwardly projecting T-shaped arm 48, the head 49 of which is disposed substantially parallel to the outer vertical edges of the jacks a, beyond the circle described by the outer ends of the butts 5i) projecting'outwardly from the said outer edges of thejacks 8. If for any reason the resilient band 9, which retains the jacks in position against centrifugal force produced by the rapid rotation of the needle cylinder 5 and jack ring 6, becomes displaced or broken, permitting the jacks to move radially outward beyond their normal predetermined limits as defined by the band 9, such projecting jack or jacks will engage the head 49 of the T-shaped arm 43 of the jack detector 45, whereby the jack detector 45 will be swung about its pivot 46 in the direction of the arrow shown in Fig. 4, which, by reason of engagement of the finger 43 of the jack detector 45 with the outer end of the arm 42 of the needle detector 36, will cause the needle detector 36 to be swung about its pivot in the same manner as heretofore described, to effect immediate stopping of the machine.

Bearing against the opposite side of the arm 42 of the needle detector 36, from that engaged by the finger 43 of the jack detector 45, is one end 51 of a trip lever 52. The trip lever 52 is pivoted at 53 to the frame of the machine, the pivot in the present instance being secured to a bar 54 which in turn is secured to the frame I by screws 55, 55.

One end of the bar 54 provides a bearing for a horizontally slidable trip rod 56, a second bear-' ing for said trip rod being provided by and in a bracket 51 secured to the base plate 2 of the machine. The trip rod 55, while being permitted to slide freely in a longitudinal direction in the bearings formed in the bar 54 of the bracket 51, is prevented from rotating within the bearings formed in the elements 54 and 51 respectively, by reason of its being flattened, as at 58, for engagement with a. correspondingly fiat face 59 in the bearing formed in the bracket 51.

Secured to the trip rod 56, in spaced relation to the bar 54, is a collar 60, between which and one side of the bar 54 is disposed a compression spring 6i. The spring 6| encircles the trip rod 56 and tends to move said trip rod axially in the direction of the arrow 0 (Fig. 1). The trip rod 56 is retained against movement in the direction of the arrow 0 under the influence of the spring 6|, by reason of a latch arm 62, forming part of the trip lever 52, normally occupying a position in a groove 63 formed in the trip rod 56, said latch arm 62 bearing against one side of the bar 54 through which the trip rod 56 slides, in the mannerillustrated in Fig. '7.

The end of the trip rod 56 which projects beyond the bracket 51 is provided with a horizontally inclined cam surface 64 which, when the trip rod 56 is projected axially in the direction of the arrow 0 (Fig. 1) under the influence of the spring 6i, strikes the vertical pin l8 of the shipper latch l9, thereby breaking the toggle formed between the latch l9 and lever l1 and causing the latch l9 to swing about its pivot 20, in the direction of the arrow shown in Fig. 6, whereby the lower end of the pin I8 is released from the abutment 24 of the belt shipper 23, permitting the shipper to move to the right, as shown in Figs. 1 and 6, to carry or to shift the driving belt from the tight to the loose pulley of the machine in the manner above noted.

The release of the trip rod 56, to effect stopping of the machine in the manner noted, is effected by a rocking of the trip lever 52 about its pivot 53, which is effected by a rocking of the needle detector 36, or the jack detector 45, about its pivot under circumstances such as those noted above. Rocking of the trip lever 52 causes the latch arm 62 to be raised out of the notch 63 in the trip rod 56, whereby the spring 6| will immediately project the trip rod 56 in the direction of the arrow 0 (Fig. 1) causing the inclined surface 64 of the arrow head 65 of the trip rod 56 to engage the pin [8 in the manner above noted.

The needle detector 36 is maintained in a normal operative position with respect to the needles 1 by the outwardly extending arm 42 thereof resting against a vertical abutment 66 on the slide 33 which permits rotation of the detector in but one direction about the post 35. The

said normal positioning of the detector 36 relative to the needles 1 is partly attained by the arm 42 being disposed under a horizontal abutment 61 which, together with the vertical abutment 66, is provided by an undercut ear 68 projecting vertically from the slide 33.

When the needle detector 36 is rocked in a horizontal plane about its vertical pivot 35 to a position wherein the face of the arm 42 that is normally engaged by the finger 43 of the jacket detector 45 passes along the horizontal abutment 61 into line with or beyond a second vertical abutment 66 formed by one edge of the ear 68 the said needle detector will be raised vertically on its pivot 35, by a spring 10 encircling the pivot post 35 of the needle detector 36 and disposed between the upper surface of the slide 33 and the underside of the hub of the needle detector 36, whereby the horizontal plane of the needle detector will be shifted with respect to the plane of the horizontal abutment 61, into a position wherein the finger-engaging side of the arm 42 of the needle detector will strike the vertical abutment 69 and prevent the needle detector from automatically returning to or reassuming its normal detecting position. Thus the machine cannot be started until the needle detector is again depressed, against the action of its elevating spring 16, to a position wherein the upper side of the arm 42 may slide under the horizontal abutment 61.

During a horizontal rocking of the needle detector 36 and the arm 42 to which said detector is secured the tine 31 operates between a pair of the needles in substantially the same manner as a tooth of one gear rolling between a pair of teeth of an intermeshing gear which moves the hook 39 of the tine 38 clear of the hooks of the needles and at the same time slides the arm 42 along the underside of the horizontal shoulder 61,, said shoulder being sufliciently long to prevent rising of the detector 36 until the hook 39 is clear of the needle hooks whereupon the arm 42 rides off the end of the shoulder 61 and the spring 16 raises the detector 36 while the momentum attained by the detector 36 during its movement by the intermeshing relation of the tine 31 with the needles throws the detector into and through the dotted line position in Fig. 2 to the broken line position in said figure clear of all the needles.

The needle detector 36 remains in the needle U detecting position hereinbefore described only during circular knitting. During reciprocating knitting the needle detector 36 is moved, substantially radially, outwardly beyond the circle described by the rotation of the needles 1, 7, hence the mounting of the needle detector 36 on the radially movable slide 33.

In order to shift the slide 33 and consequently the needle detector 36 to their outer inoperative positions during reciprocating knitting, the outer end of the slide 33 is provided with a vertically disposed head 1'5, providing upper and lower shoulders on the slide. Behind the upper shoulder 15a is normally disposed one arm 16 of a retracting lever 11 which is pivoted at 18 to a fixed portion 16 of the machine. The lower arm 86 of the retracting lever 11 is pivotaliy connected at 6! toone end of a retracting bar 62 which is slidably mounted adjacent the lever 11 in a bracket 83 secured to the frame i of the machine. The opposite end of the retracting bar 82 is slidably mounted in a bracket 86 secured to the base plate 2 of the machine. The end of the retracting bar 82 which projects beyond the bracket 84 is provided with a retracting cam surface which normally engages or is engaged by the shifter fork M. A spring 85 stretched between the retracting bar 82 and the bracket 84 tends to maintain the cam surface 85 in constant contact with the shifter fork M.

When the shifter fork- M is raised, to effect circular knitting in the manner above noted, the shifter fork i4 sliding against the retracting cam surface 85 slides the retracting bar 82 longitudinally in the direction of the arrow (Z (Fig. 1), whereby the retracting lever H is swung about its pivot l3, the arm 16 of said lever mov'ng inwardly toward the needle cylinder 5, thereby permitting the springs 3% to move the sliding support 33 inwardly in its guideway 32 in the pedestal 3!, whereby the needle-engaging end of the needle detector 36 is brought into cooperative relation to the needles I. When the shifter fork i4 is moved downwardly, to effect reciprocating knitting, the spring 86 moves the retracting bar 82 longitudinally in the direction opposite to that indicated by the arrow (1, thereby rocking the retracting lever T1 about its pivot, causing the upper arm 16 of the retracting lever I? to move outwardly and in so doing to engage the shoulder 15a of the slide whereby the said support 33 is moved outwardly against the action of the springs 34, the needle detector 35 being thereby moved to an inoperative position with respect to the needles 7.

The machine as sold on the market is equipped with a slide-operating lever 9i! which, under the control of pattern mechanism (not shown) moves in the direction of the arrow e when a stocking has been completed. The needles 1?, i are thereby leveled to a common plane in order that a new top may be transferred onto the needle of the machine, for the starting of a new stocking.

During the topping or transferring operation, it is desirable to have the needle detector 36 in an inoperative position and for this purpose, according'to the principles of the present invention, the slide operating lever 90 is provided with a vertical extension 9| which projects above the normal extreme height of the lever to a position behind the lower shoulder 15b of the slide 33 to be engaged by the inner end of a set screw 93 carried by the lower portion of the head 15. Therefore, as the slide-operating lever 98 moves in the direction of the arrow e, to efiect leveling of the needles 1, (Fig. 1), the slide333 and consequently the needle detector 36 are moved outwardly in substantially the same manner as described above.

In order to limit the movement of the trip rod 56 in the direction of the arrow c (Fig. 1), the said rod is provided with a collar 94 arranged to engage the bearing bar 54 when the trip rod 56 moves in the direction of the arrow 0, after its release from the latch 52.

In order to reset the trip rod 55, the end thereof projecting beyond the bearing bar 54 is provided with a handle 95, by which the trip rod 56 may be moved in a direction opposite to that indicated by the arrow 0 until the outer end of the latch 62 of the trip lever 52 is seated in the notch 63 of the trip rod 56.

Shifting of the belt shipper 23 to carry the belt from the loose to the tight pulley of the machine, for restarting of the machine is effected in the ordinary manner, the arm 27 of the starting lever 28 engaging a projection 96 on the belt shipper 23 and sliding the shipper 23 to the left until the pin l8 on the latch i 9 is again positioned behind the abutment or shoulder 24 on the belt shipper 23.

Movement of the slide-operating lever 90 in g the direction opposite to that indicated by the arrow c (Fig. 1), to release the slide 33, is normally affected by a spring 91.

I claim: 7

1. In a circular knitting machine comprising needle-controlling jacks normally disposed Within a circle of predetermined diameter, and a stop motion, the combination therewith of a jack detector arranged in a vertical plane intersecting said circle to be engaged by a radially extending side of a jack extending beyond said circle, and means operable by said jack detector for actuating said stop motion.

2. In a circular knitting machine employing longitudinally operable needles, jacks controlling said needles and normally disposed in predetermined relation thereto, and a stop motion, the combination of an inoperable needle detector, a misplaced jack detector adjacent the first said detector, and means adjacent and common to both and operable by either of said detectors for actuating said stop motion.

3. In a circular knitting machine employing latch needles, jacks controlling said needles and normally disposed in predetermined relation thereto, and a stop motion, the combination therewith of a closed latch detector, a misplaced jack detector adjacent the first said detector, and means adjacent and common to both and operable by either of said detectors for actuating said stop motion.

l. In a circular knitting machine employing vertically operable latch needles, jacks disposed in predetermined relation'to the needles for controlling said needles, and a stop motion, the combination therewith of a closed latch detector, an inoperable needle detector adjacent the first said detector, a misplaced jack detector adjacent the first two detectors, and means common to all and operable by any one of said detectors for actuating said stop motion.

5. In a circular knitting machine employing vertically operable latch needles, jacks disposed in predetermined relation to the needles for controlling'said needles, and a stop motion, the combination therewith of a closed latch detector, an inoperable needle detector, a common mounting for said needle detectors, a misplaced jack detector, means common 7 to said detectors for actuating said stop motion, shiftable means for effecting circular or reciprocatory knitting cycles by said needles, and means operable by said shiftable means for withdrawing said mounting and 6. In a circular knitting machine employing longitudinally operable latch needles, shiftable means for effecting circular or reciprocatory knitting cycles bysaid needles, and a stop motion, the combination therewith of a closed latch detector, an inoperable needle detector, a common mounting for said detectors, means common to said detectors for actuating said stop motion, and means operable by said shiftable means for withdrawing said mounting and'said detectors during reciprocatory knitting cycles as determined by said shiftable means.

7. In a circular'knitting machine employing longitudinally operable latch needles, means controlling leveling of said needles, and a stop motion, the combination therewith of a closed latch detector, an inoperable needle detector, a common mounting for said detectors, means common to said detectors for actuating said stop motion, and means operable by said needle leveling control means for withdrawing said mounting and said detectors during the leveling of said needles.

8. In a circular knitting machine employing longitudinally operable latch needles, means for controlling operation of said needles to effect circular or reciprocatory knitting cycles thereby, means for controlling leveling of said needles, and a stop motion, the combination therewith of a closed latch detector, an inoperable needle detector, a common mounting for said detectors means common to said detectors for actuating said stop motion, and means common to said controlling means for withdrawing said detectors upon predetermined operation of one of said controlling means.

9. In a knitting machine comprising a circle of elements adapted normally to perform predetermined operations in the knitting of successive courses of stitches by said machine, a stop motion, a detector pivotally mounted outside said circle and having one end disposed at said circle, for engagement with individual elements of said circle under abnormal conditions afiecting said knitting, a longitudinally movable spring actuated trip rod for effecting operation of said stop motion and provided with a retaining shoulder,

and a pivotally mounted lever having one arm engaging said shoulder for withholding said trip rod and a second arm directly engaging and operable by said detector to effect release of said trip rod.

10. The combination of a series of needles, a support adjacent said needles, a post on said support, a detector pivotally and slidably mounted on said post, an abutment engaging said detector and allowing pivotal movement thereof in but one direction about the post for maintaining the detector in a normal position in cooperative relation to said needles, resilient means for sliding said detector axially of said post, a second abutment normally holding said detector against the action of said resilient means to maintain the detector in said normal position, and a third abutment preventing return of said detector to said normal position upon its release from the first two said abutments by engagement with one of said needles.

11. The combination of a series of needles operable in a predetermined plane, a post spaced from the plane of the needles, a detector pivotally and slidably mounted on said post and comprising a needle-engaging arm at one side of said post with its free end disposed at said plane, and a positioned arm at the opposite side of said post, a pair of laterally spaced substantially parallel abutments for engagement with said positioning arm, a third abutment substantially at right anbles to and connecting said laterally spaced abutments, and means normally pressing said positioning arm into engagement with said third abutment arm for sliding said detector axially of and on said post past said third abutment upon piv- 5 otal movement of the detector about said post by engagement of the needle-engaging arm with one of said needles swinging the retaining arm from one to the other of the first said pair of abutments.

12. The combination of a series of needles operable in a predetermined plane, a series of jacks in cooperative relation to said needles, a needle detector pivotally mounted adjacent said needles, a jack detector pivotally mounted adjacent said jacks and operatively engaging said needle detector, an abutment engaged by one of said detectors for maintaining said detectors in operative relation to said needles and jacks respectively, and means for sliding the abutment-engaging detector axially of and upon its pivot upon release of said detector from said abutment by pivotal movement of one of said detectors about its pivot.

13. The combination of a series of needles operable in a predetermined plane, a series of jacks in cooperative relation to said needles, a support movable toward and from the plane of the needles, a needle detector pivotally mounted on said movable support adjacent said needles, a jack detector pivotally mounted adjacent said jacks and operatively engaging said needle detector, an abutment on said movable support engaged by said needle detector for maintaining said detectors in operative relation to the needles and jacks respectively, means for sliding the needle detector axially of and on its pivot and relative to said jack detector upon release of the needle detector from said abutment upon pivotal movement of one of said detectors, and means for moving said support and said needle detector out 0 of cooperative relation to said needles while maintaining operative relation between said needle and jack detectors.

l4. f'he combination of a series of longitudinally operable latch needles individually movable in a common plane, and a detector comprising a an arm provided with one finger intersecting the plane of movement of said needles, and a second finger provided with a bent end disposed substantially parallel to the said plane of movement of said needles, for engagement respectively upon lateral relative movement between the series of needles and said detector with a needle out of normal lateral alignment with adjacent needles of said series and for engagement with a closed latch of one of said needles among a group thereof wherein the latches are normally.open.

JOHN A. LOCKE. JOHN CAMPANELLA. 

